1. Field of the Invention
The invention relates to a detector for atrial fibrillation and atrial flutter. Both types of atrial tachycardia are commonly referred to as AF herein after.
The invention also relates to an implantable medical device such as an implantable cardiac pacemaker or an implantable cardioverter/defibrillator (ICD) incorporating such detector and a method for detecting atrial fibrillation and atrial flutter.
2. Description of the Related Art
Atrial fibrillation is a cardiac state of disordered excitation of the atrial myocardium, possibly revolving around atrial flutter, in which the affected atrium is nearly unable to contribute its share to cardiac output. In an intraatrial electrocardiogram (intraatrial EGM) AF can be recognized by a high frequency atrial rate and a low amplitude.
Atrial fibrillation can be treated by means of implantable medical devices such as atrial defibrillators. Examples of atrial defibrillators and detectors for atrial fibrillation can be found in U.S. Pat. Nos. 5,267,559, 5,433,729, 5,464,431, 5,464,432, 5,486,199 and 5,720,295.